Study On The Application Of Rotating-stream-tray In Fuel Gas Desulphurization By Natrium-alkali

Considering the application of Rotating-stream-tray(RST) scrubber in fuel gas desulphurization by natrium-alkali, this thesis has investigated the effects of different factors on the efficiency of fuel gas desulphurization, plate efficiency, dust removing efficiency and fluid mechanics characteristics of RST.Numerical experiments were carried out to simulate the flow field in RST scrubber by computational fluid dynamics (CFD) software FLUENT. The calculated results showed that the gas velocity at the middle of RST was largest, but the gas velocity from this point to two tips of RST gradually declined, moreover, the gas velocity near to blanking plate was small, at the same time, the static pressure was lower at blanking plate, but higher near to tower wall.A mathematic model for sulfur dioxide absorption equilibrium in sodium alkali aqueous solution was established. The results indicated the modification of activity coefficient would influence equilibrium curves; furthermore, the conditions of alkali-adsorption solution affected the trend of the absorption equilibrium curves. Desulphurization experiments showed the SO₂ removal efficiency increased first, then decreased with the increase of sodium ion concentration, and the critical sodium ion concentration was about 0.8mol/L; SO₂ removal efficiency as well increased with pH, but almost kept at the same level when pH at 6.7⁷.9; Obviously, SO₂ removal efficiency increased with the ratio of liquid/gas in a linear mode; in addition, SO₂ removal efficiency increased with the increase of the inlet SO₂ concentration as SO₂ concentration was low, and reduced when the SO₂ concentration was higher than a certain value, this proved that it existed a optimum SO₂ concentration for RST on a certain experimental conditions. The plate efficiency for RST decreased with sodium ion concentration and pH increasing.From the measurement of pressure drop, it was found that the pressure drop of wet plate at experimental conditions was low, and changed little at certain range of liquid/gas ratio. The dust removal experiments showed that the efficiency of dust removal could reach to 60% even at a smaller ratio of liquid /gas, and almost kept at the same level with the variation of dust concentration in lab conditions.The experiments and theory analyses above confirm that RST has many advantages such as higher desulphurization efficiency, more load, lower pressure drop, wider range of operation and better dust removal efficiency, which is qualified to simultaneously realize the two objects of desulphurization and dust removal in FGD industry.